Sr4AlNbO8: A new crystal structure type determined from powder X-ray data

The crystal structure type of Sr4AlNbO8 is new, and may be described as a three-dimensional polyhedral network resulting from the corner-sharing of NbO6 and Sr1O6 octahedra and AlO4 tetrahedra. Also, the other strontium atoms (Sr2, Sr3, and Sr4) occupy the larger cavities surrounded by oxygen atoms.